Where does “trichloroethene” come from?

trichloroethene (English) comes from English tri-, from Sanskrit त्रि, from Proto-Indo-Aryan tráyas, from Proto-Indo-Iranian tráyas, from Proto-Indo-European *tréyes.

Ancestry of “trichloroethene”, step by step

Step	Language	Word	Meaning
1	English	tri-	API; three; Used in combination with a known...
2	Sanskrit	त्रि	three
3	Proto-Indo-Aryan	tráyas	three
4	Proto-Indo-Iranian	tráyas	three
5	Proto-Indo-European	*tréyes	—

Every word from Proto-Indo-European *tréyes →Every word from English tri- →Every word from Proto-Indo-Iranian tráyas →